Push bench guide



June 18, 1935. s, n- 2,005,328

PUSH BENCH GUIDE Filed Feb. 19, 1932 2 Sheet-Sheet l June 18, 1935. 5.SMITH 2,005,328

PUSH BENCH GUIDE I Filed Feb. 19, 1932 2 Sheets-Sheet 2 Mil! NTR'

u I I 1 i I Patented June 18, 1935 UNITED STATES PUSH BENCH GUIDE-Sydney Smith, London, England, assignor to Wellman Seaver Rolling MillCo. Ltd., London, England, a British Company Application February 19,1932, Serial No. 594,037

14 Claims.

- This invention relates to the manufacture of tubes by the push benchprocess. Itrelates more particularly to apparatus for the manufacture oftubes by the push bench process ineluding means separate from the benchdies for guiding the mandrel and blank in proper cooperativerelationship with respect to the dies.

In the push bench process of-tube manufacture a heated billet is piercedin a press to form a bottle open at one end and closed at the other, andsuch bottle is then placed over the end of a mandrel and pushed througha series of aligned dies to thin and elongate the same. The dies atthefore part of the push bench are relatively closelyspaced due to theshortness of the blank at that point. The dies at the rear part of thebench are more widely spaced as the blank is elongated.

It is of course desirable that the blank as formed on the push benchhave uniform wall thickness throughout. Such uniform wall thickness isdependent upon accurate centering of the mandrel with respect to thedies so that the distance between the mandrel surface and the surface ofeach die through which it passes will be the same at all pointscircumferentially of the mandrel.

There is a tendency, due'to the weight of the mandrel, particularly inthe formation of tubes of the larger sizes, for the mandrel tosomewhatmore highly compress the lower portion of the blank than the upperportion as it passes through the dies, resulting in a tube whose wallthickness is less at the bottom than at the top. In' order to overcomethis tendency I provide means separate from the dies for guiding themandrel and blank to insure as nearly as possible that the mandrel willenter each die substantially coaxially therewith and will remain coaxialwith the die as long as any portion of the mandrel is within it.Thisresults in the formation of tubes of substantially uniform wallthickness throughout.

Other objects and advantages of theinvention will become apparent as thefollowing description ofcertain present preferred'embodiments thereofproceeds.

In the accompanying drawings 1' have shown certain present preferredembodiments of the invention, in which Figure l is a transversecross-sectional view of a push bench showing means for guiding a mandreland blank;

Figure 2 is a horizontal cross-sectional view taken on the line IIII' ofFigure 1;

Figure 3 is a transverse cross-sectional View. of a push bench showingmodified guiding means; and

Figure 4 is a cross-sectional view taken on the line IVIV of Figure 3.

Referring more particularly to- Figures 1 and 2, the bed of the the pushbench is designated generally by reference numeral 2 and is provid-' edwith grooves 2a for receiving and retaining dies adapted to cooperatewith a mandrel, to thin and. elongate a blank into a finished tube. Oneof the dies isshown at 3, being carried by a holder 4 mounted in the bedand retained in place by plates 5 fastened to the bed by bolts" 7 6provided with nuts 1. The dies may be of any 15 preferred construction,as well known in the art.

The bed 2 is provided opposite each groove 2a with generally downwardlyand outwardly extending oppositely positioned hollow projections orbosses 8 each having an inturned'fiange 9 at its extremity. Fittingwithineach projection 8 and seated against the flange 9 thereof is acol-' lar It through which is threaded a bolt H. Each bolt H has arelatively small neck 12 and an enlarged head I 3 adapted to bepositioned within a groove !4 in a block 15 slidably mounted in the boreof the corresponding extension 8. The outer extremity of. each bolt I!is squared at it for the receptionof a wrench. Rotation of each boltcauses it to moverelatively to its collar In whereby to adjustablypositionthe corresponding block l5'as may be desired within the bore ofthe corresponding extension 8. Each bolt is provided with a compressioncollar H, a washer l8 and a nut 19 for looking it in desired adjustedpositions; In the position shown in Figure 1 both blocks l5 are in theirlowermost possible positions in contact with the respective collars l0.

Mounted in the bed 2 for vertically slidable movement inone of thegrooves 2a is a roller frame '20 (Figure-2) having a central opening.and receiving the opposite extremities of a shaft 2!. The shaft 2i isfixedly positioned in the roller frame 2!! by set screws 22. Journaledon 45 the shaft 2! by roller bearing means 23, which may be of anypreferred construction, andpositioned within the opening in the rollerframe, is a roller 24 having a concave outer surface 25.

The opposite extremities of the roller frame 20 are carried by therespective blocks I5. When such blocks are moved inwardly of theextensions 8 the roller frame 20 is elevated-with respect to the die 3.The roller 24 is preferably positioned immediately adjacent the entranceend of the die 3 and is adjusted at such a height that the mandrel andblank carried thereby in advancing through the bench will rest upon theroller and be guided thereby so that the mandrel is coaxial with thedie. This prevents the mandrel from more highly compressing the lowerportion of the blank than the upper portion due to the weight of themandrel, as might occur if the mandrel and blank were simply movedthrough the die without being guided. This is particularly true when anunsupported portion of the mandrel of substantial length enters the die,as the weight of the mandrel will cause its nose to sag, if only veryslightly. Every effort is made to eliminate sagging by constructingmandrels of special alloy steels and by designing them in such mannerthat they Will not easily bend, but the weight of the mandrels and theunsupported length thereof is so great that it is virtually impossibleto entirely eliminate sagging of the forward end of the mandrel at allpoints along the ring bed without some guiding means.

It is'not essential that the mandrel and blank be guided in thehorizontal direction because there are no unbalanced forces tending tomove the mandrel in either horizontal direction as the force of gravitytends to move it downwardly.- Therefore, the mandrel will substantiallycenter itself in a horizontal plane when passing through the dies. InFigure 1 the roller 24 isshown as being mounted on the shaft 2! in suchmanner that it may move axially to a limited extent to accommodateitself to the hori- "i' zontal position of the mandrel and blank.

'A modified construction is shown in Figures 3 and 4 in which partswhich correspond to parts in Figures 1 and 2 have the same referencenumerals but with a prime afiixed. Each block l5, instead of simplyserving as a support for one end of a roller frame, is providedintegrally at its inner extremity with a yoke 26 in which is suitablyjournaled a shaft 21 carrying a roller 28. The two rollers 28 cooperateto support and position the mandrel and blank, as shown in Figure 3.This method of support insures somewhat more perfect positioning thanthat of Figures 1 and 2 In Figure 3 the mandrel is indicated at 29 andthe blank at 30.

Figure 4 shows one set of guiding rollers immediately before and anotherset immediately behind the die 3. The rollers thus assist in positioningthe mandrel and blank both before and after they pass through the die.As shown in the drawings, the rollers behind the die are at a slightlyhigher'elevation than the'rollers in front of the die to compensate forthe reduction of the blank in the die, which raises its lower u ace Thegrooves 2 are uniformly spaced along the ring bed and are of uniformdimensions. In line with each groove is a pair of the projections -orbosses 8; The parts are so proportioned that each groove may be used forthe reception either of a die or of a roller frame. Therefore, greatflexibility of arrangement of the dies and rollers is provided for.

Various combinations and arrangements of the rollers may be utilized.For example, it may be desired to have rollers such as shown in Figures,3 and 4 immediately in front of a die and aroller such as shown inFigures 1 and 2 behind such-die, as the former somewhat more exactlyposition the mandrel and blank, the latter simply serving to support aportion of the weight thereof. Likewise the spacings of the dies andguides may be varied. For example, it may be desired to use guidesapproximately halfway between adjacent dies so as to reduce the numberof guides used in the bench. Although the guides are shown as being inthe form of anti-friction rollers, they may assume other froms.

The term tube is used herein as a word of definition and not oflimitation, and is not to be construed as denoting only that class ofarticles commercially known as tubes.

While I have shown and described certain present preferred embodimentsof the invention, it is to be distinctly understood that the same is notlimited thereto, but may be otherwise variously embodied within thescope of the following claims.

I claim:

1. Apparatus for the manufacture of tubes by the push bench process,comprising a mandrel, a plurality of dies for cooperation with themandrel to thin and elongate a blank, and non-yieldably mounted meansseparate from the dies having a portion engaging the blank throughoutsubstantially less than its entire periphery for guiding the mandrel andblank in proper cooperative relationship with respect to the dies.

2. Apparatus for the manufacture of tubes by the push bench process,comprising a mandrel, a plurality of dies for cooperation with themandrel to thin and elongate a blank, and means mounted againstretractive movement in any direction separate from and positionedintermediate the dies for guiding the mandrel and blank in propercooperative relationship with respect to the dies.

3. Apparatus for the manufacture of tubes by the push bench process,comprising a mandrel, a plurality of dies for cooperation with themandrel to thin and elongate a blank, and nonyieldably mountedanti-friction means separate from the dies engaging the blank in guidingrelationship for guiding the mandrel and blank in proper cooperativerelationship with respect to the dies.

4. Apparatus for the manufacture of tubes by the push bench process,comprising a mandrel, a plurality of dies for cooperation with themandrel to thin and elongate a blank, and means separate from the diesand adjustable toward and away from the axis of the mandrel for guidingthe mandrel and blank in proper cooperative relationship with respect tothe dies, said means being adapted to engage the blank and beingnon-yieldable when in engagement therewith.

5. Apparatus for the manufacture of tubes by the push bench process,comprising a mandrel, a plurality of dies for cooperation with themandrel to thin and elongate a blank, and nonyieldably mounted meansseparate from and intermediate the dies and adapted to engage the blankat points spaced circumferentially thereof for guiding the mandrel andblank in proper cooperative relationship with respect to the dies.

6. Apparatus for the manufacture of tubes by the push bench process,comprising a mandrel, a plurality of dies for cooperation with themandrel to thin and elongate a blank, and non-yieldably mounted meansseparate from the dies having a portion engaging the blank throughoutsubstantially less than its entire periphery and positioned adjacent theentrance end'of at least one thereof for guiding the mandrel and blankin proper cooperative relationship with respect thereto.

7. Apparatus for the manufacture of tubes by the push bench process,comprising a mandrel, a plurality of dies for cooperation with themandrel to thin and elongate a blank, and means separate from the diesand positioned adjacent both ends of at least one thereof for guidingthe mandrel and blank in proper cooperative relationship with respectthereto, said means being adapted to engage the blank and beingnonyieldable when in engagement therewith.

8. Apparatus for the manufacture of tubes by the push bench process,comprising a mandrel, a plurality of dies for cooperation with themandrel to thin and elongate a blank, and roller means separate fromand'positioned intermediate the dies and adjustable toward and away fromthe axis of the mandrel to assume guiding position in contact with theblank for guiding the mandrel and blank in proper cooperativerelationship with respect to the dies. 7

9. Apparatus for the manufacture of tubes, comprising a push bench, amandrel, dies in the push bench for cooperation with the mandrel to thinand elongate a blank, means mounted in the push bench for slidablemovement transversely thereof, and means connected with said firstmentioned means for engaging the blank to guide the mandrel and blank inproper cooperative relationship with respect to the dies.

10. Apparatus for the manufacture of tubes by the push bench process,comprising a mandrel a plurality of dies for cooperation with themandrel to thin and elongate a blank, means separate from the dies forengaging the blank to guide the mandrel and blank in proper co operativerelationship with respect to the dies, and screw means for adjusting theposition of said first mentioned means.

11. Apparatus for the manufacture of tubes, comprising a push bench, amandrel, dies in the 'push bench for cooperation with the mandrel tothin and elongate a blank, a support mounted in the push bench forslidable movement transversely thereof, means for maintaining thesupport in desired adjusted positions, and antifriction means carried bythe support for engaging the blank to guide the mandrel and blank inproper cooperative relationship with respect to the dies.

12. Apparatus for the manufacture of tubes by the push bench process,comprising a bed having grooves therein, and die means andnonretractible mandrel guiding means positioned opposite a portion onlyof the periphery of the mandrel selectively disposable in such grooves.

13. Apparatus for the manufacture of tubes by the push bench process,comprising a mandrel, a pluralityof dies for cooperation with themandrel to thin and elongate a blank, and means in advance oftheposition of the forward end of the mandrel at the beginning of itsstroke mounted against retractive movement during operation of theapparatus for guiding the man- 1 drel and blank in proper cooperativerelation-

